The golden oldies, some from as far as Australia, proudly clutched their invitations as they queued for hundreds of yards around the Palace, the lines almost reaching Hyde Park corner.
The mood was quiet, predictably orderly, and humorous. One pensioner remarked: "You can tell we are all from the war-generation by the way we are queuing up!"
Inevitably some suffered from the long wait and the lengthy walk with several fainting in the gentle sunshine and one person collapsing inside the Palace itself, with a suspected heart attack.
All, though, were anxious to meet The Queen and Prince Philip to share the one thing they all had in common - the year of their wedding.
Mr Leow, a part-time actor who appeared in James Bond films, such as Live and Let Die and Goldfinger added: "When we got married in Guyana we had no idea we would even come to this country let alone get asked to Buckingham Palace."
Mrs Ottilie Bishop, from Newcastle-under-Lyme, came alone after her husband fell ill two days ago. "I hope they will let me in on my own. I am really looking forward to it, after all she won't ask me again will she?"
As they filed inside the gates, the couples praised The Queen and Prince Philip for their years of long marriage. Though many among the 4,000 felt the Royal children had let the older generation down. All had the own pet theories about the success of a long marriage. Wheel-chair bound Marjory Bushell, 70, from Portswood, Southampton, who was with her husband Harry, said: "You should never go to bed on a quarrel. It is an achievement to be married this long whether you're The Queen or a commoner."
Joe and Enna Turner, from Douglas, on the Isle of Mann, said it came down to determination: "Our generation worked hard at marriage, that's how it was," said Mr Turner. "It must be harder for The Queen and The Duke being in the public eye."
Another couple standing nearby added: "The secret is a good row, good making up and getting on with it."
Some reflected on the contrast between the lavish Palace reception and their more modest celebrations. Mrs Leow said: "We had a little celebration in Croydon with our children - I don't think I could afford 4,000 guests on my pension."Reuse content